Fibrous insulation is manufactured by forming fibers from a molten mineral bath, which are forced through a spinner rotating at a high number of revolutions per minute. Fine fibers are produced thereby. To manufacture loose fill insulation, or wool type insulation, a plurality of the fibers are loosely accumulated together to form loose fill insulation. Alternatively, to make a mat of insulation, a plurality of the fibers are sprayed with a fluid binder mix or powder binder, typically a phenolic resin, a thermoplastic, a thermosetting plastic, an acrylic, vinyl-acrylic or other soluble polymer. The fibers are accumulated on a conveyer to form a thick mat. The binder is then cured in a curing oven. The uncured mat may be further adapted for duct liner, duct board or pipe insulation before curing. Alternatively, the mat is then sliced and/or chopped into individual insulation batts. In some cases, a facing material is applied to cover at least one side of the mat with a vapor retarder.
Fibrous insulation is vulnerable to fungal growth due to exposure to microbiological organisms, especially when the insulation is installed in damp environments, such as, subterranean basements, and poorly vented cavities under a roof, for example.
U.S. Pat. No. 6,399,694 discloses a practice of adding a fungicide to a batt while still on a conveyor, but subsequent to manufacture of fibers that are bonded together by a binder. U.S. Pat. No. 6,399,694 discloses a further practice of adding a fungicide to a batt in the field, at a location where the batt is to be installed. In each of these disclosed practices, the fungicide is externally applied to the binder, and the binder itself is not mold resistant. In each of these disclosed practices, manufacturing controls are lacking to control the fungicide concentration and to control dispersal of the fungicide in an even distribution throughout the batt. WO 02/092578 A1 discloses borax for infrared absorbing and scattering, but not for a fungicide.
Thus, prior to the invention, adding fungicide to a completed batt lacks manufacturing controls to apply the fungicide with a controlled concentration. For example, manufacturing controls would be needed to prevent the fungicide from being handled and applied at potentially toxic levels of concentration. Further, manufacturing controls would be needed to establish a justification for advertising and labeling the fibrous insulation as being mold resistant. Further, for example, in the future, a manufacturer of a fungicide may develop a recommended concentration to resist fungal growth, which would require manufacturing controls to apply the fungicide at the manufacturer's recommended concentration.
Lacking manufacturing controls while adding a fungicide to a batt could induce instability in the measured physical properties of the batt. Thus, controlled amounts of fungicide avoid inducing the physical instability as found by testing the batt to meet industry standards for thickness recovery and other physical properties.
Accordingly, there is a present need for a fibrous insulation having a controlled fungicide concentration. Further, there is a present need for a method of making a fibrous insulation with a controlled fungicide concentration.
Further, there is a present need for a fibrous insulation having a dispersed additive that serves a useful function in the fibrous insulation, and further a fungicide is combined with the dispersed additive. Further, there is a present need for a fibrous insulation having a dispersed additive that is mold resistant. Further, there is a present need for a manufacturing process for dispersing a fungicide by a binder as the dispersed additive that bonds fibers to one another to make a mat of insulation.
Further, there is a present need for a mat or loose fill, fibrous insulation having a dispersed fungicide. Further, there is a present need for a manufacturing process for dispersing a fungicide throughout a fibrous insulation.